In the state of the technology, a parking aid for motor vehicles is known, which possesses a detector that can be mounted on the rear of the motor vehicle and an information provider in or on a driver's cab. The detector, which can be a radar, imaging or other electromagnetic, electro-optic or sonic device, possesses a sensor and a control apparatus. Control signals can be transmitted from the information provider to the control apparatus for the regulation of the detector. Further, signals from the detector which advise of a situation behind the motor vehicle can be transmitted to the information provider to inform the driver about a situation behind the motor vehicle. If the detector is an image sensor, the information is available to the driver by a screen display or similar device. In the case of a radar apparatus, then the information or data is delivered to the driver by an acoustic warning emanating from the information provider.
In the foregoing arrangements, the driver is assisted during a backing up operation, for example, when parking in a manner to avoid running into an obstruction such as a parked motor vehicle or the like. Presently, the connection between the information provider and the detection equipment in such parking aids is implemented by electrical wiring. However, there are disadvantages in regard to expense and labor installation time, especially when the parking aid is to be installed in an existing vehicle. Additionally, if the parking aid is to be used on a truck with a pulled or saddled trailer, a releasable connection must be provided between the information provider on the truck and the detection device on the back of the truck or trailer assembly in order to uncouple the pulled or saddled trailer.